This invention relates in general to a removable cartridge for an information storage device and, more particularly, to a method and apparatus for electrically coupling components within such a cartridge.
Over the past twenty years, computer technology has evolved very rapidly. One aspect of this evolution has been a progressively growing demand for increased storage capacity in memory devices, especially where the information storage medium is disposed in some form of removable cartridge. In this regard, just a little over a decade ago, the typical personal computer had a floppy disk drive which accepted floppy disk cartridges that contained 5.25xe2x80x3 disks having a storage capacity up to about 720 KB per cartridge. Not long thereafter, these devices gave way to a new generation of floppy disk drives which accepted smaller floppy disk cartridges that contained 3.5xe2x80x2 disks having higher storage capacities, up to about 1.44 MB per cartridge.
Subsequently, as the evolution continued, a further significant increase in storage capacity was realized in the industry by the introduction of a storage system having removable cartridges containing floppy-type disks with storage capacities on the order of 100 MB to 250 MB. Systems of this are commercially available under the tradename ZIP from Iomega Corporation of Roy, Utah, which is the Assignee of the present application. Thereafter, another significant increase in storage capacity was realized by the introduction of a system having removable cartridges with storage capacities on the order of 1GB to 2GB. Systems of this type are also available from Iomega Corporation, under the tradename JAZ. The cartridges used in this system had a hard disk in an unsealed housing, with the read/write head in the drive. These two products have each enjoyed immense commercial success. Nevertheless, the demand for still greater storage capacities in removable cartridges continues to progressively increase, such there is a current need for cartridges capable of storing 5GB to 20 GB, or even more.
The types of removable cartridges discussed above each contain a rotatably supported storage medium within an unsealed housing. The read/write heads, with associated circuitry and support structure, are in the drive rather than in the cartridge. Significantly higher storage capacities exist in hard disk technology of the type used in non-removable hard disk drives, where the disk and head are both within a sealed housing. However, there are problems involved in attempting to carry use of this technology over to removable cartridges. This is due in part to the fact that a high-capacity hard disk is highly sensitive to environmental factors such as dust and static electricity. Consequently, in order to achieve high storage densities, the sealed housing is needed for the hard disk itself, as well as for some associated components, such as the read/write heads, which must be within the sealed housing and thus within the cartridge. Although some prior attempts have been made to use hard disk technology within a sealed housing in a removable cartridge, these attempts never resulted in a product which has had any significant level of commercial success. Instead, the types of cartridges discussed above continue to dominate the market.
Where a sealed housing has been used, the most typical prior approach was to incorporate the entire structure of a hard disk drive unit into the cartridge, such that the cartridge was not significantly different from a selfcontained, standalone hard disk drive unit. In a sense, this was not a true cartridge at all, but simply a complete and self-contained hard disk drive which could be removed more easily than most from the system in which it was installed. One example of such a device is a system which was commercially available as the model P3250AR removable hard disk drive from Kalok Corporation of Sunnyvale, Calif. Another example of such a system is disclosed in Blackborow et al. U.S. Pat. No. 5,041,924. Since each cartridge in this type of system is effectively a standalone, self-contained disk drive, each cartridge is relatively heavy and expensive.
A different prior approach was to split the components of a self-contained hard disk drive into two groups, and to include one group within a sealed housing in each removable cartridge, and the other group in a drive which can removably receive one of the cartridges. Examples of this approach appear in Stollorz U.S. Pat. No. 4,359,762, Iftikar et al. U.S. Pat. No. 4,965,691, Chan U.S. Pat. No. 5,214,550, Kamo et al. U.S. Pat. No. 5,235,481, Witt et al. U.S. Pat. No. 5,317,464, and Lockhart et al. U.S. Pat. No. 5,412,522. While pre-existing products using this approach were adequate for their intended purposes, they were not satisfactory in all respects, and none of them experienced any significant commercial success.
In this regard, one consideration is that this type of removable cartridge has a sealed housing with one or more electrical components therein, such as the read/write head(s), and also has a connector or some other form of input/output port on the housing, through which external circuitry can interact with the electrical components within the cartridge. The connector or port must be operatively coupled to some or all of the electrical components within the cartridge. In order to achieve the electrical coupling between the connector and components, in a manner which is likely to result in a commercially successful cartridge, it is desirable that all electrical coupling can be effected quickly and easily during cartridge assembly so as to minimize manufacturing labor costs, and that a minimum parts count be involved so as to minimize the number of parts which must be inventoried for purposes of manufacturing and repair. It is also desirable that the weight and cost of the cartridge be minimized, while optimizing reliability.
From the foregoing, it may be appreciated that a need has arisen for a method and apparatus for effectively and efficiently implementing an electrical coupling between internal components and an external port of a removable cartridge for an information storage device. According to the present invention, a method and apparatus are provided to address this need for an information storage cartridge of the type which includes a port, an information storage medium having an information storage surface thereon, a head operable to effect at least one of reading information from and writing information to the surface, and an actuator operatively coupled to the head. The method and apparatus involve: supporting the head and the storage medium for relative movement in a manner causing the head to move with respect to the surface while remaining adjacent thereto, the actuator controlling at least one component of the movement of the head relative to the surface; using a single flex circuit to electrically couple the port to each of the head and the actuator; and transmitting through the single flex circuit all electrical signals traveling between the port and each of the head and the actuator.